Engine diagnosis help in Denver? (FJ40)

[Azrael]

A weak battery will certainly not help with diagnosing the problem. I'm still thinking it's your timing/advance. Did you get the Vacuum advance connected?

I was looking at another 40 recently and it made me think of this thread. They had the vacuum advance connected to the valve on the intake manifold (in front of the carb riser) rather than connecting it to a ported vacuum connector on the carb. Not sure if this would be detrimental, but it seemed to be working in their application.

Do you still have a toyota intake manifold? and if so, can you connect your vacuum advance to that instead of nothing?

(hopefully the toyota fj40 carb gurus will chime in and school us on vacuum advance )

I did finally find the vacuum connection on the carb just shortly before Matt came over. It was plugged off with a very short piece of tube with a screw in the end. In dim light, it looked just like another adjustment screw...

From the reading I've done, it sounded like I should have it disconnected and plugged when I adjust the timing, and reconnected when I actually run the car, so this is what I've been doing. Also, from what I've read, timing with the Weber should be around 12 degree advanced. The timing light I borrowed is just the basic variety, but it sounded like 12 degrees should be when the BB is just out of view out of the bottom of the window. Whenever I got it to come into view, the engine would start to die.

 

[subzali]

Idle circuit solenoid?

 

[Azrael]

As far as I can surmise, my carb doesn't have the solenoid, though I can fit an optional add on for it.

Are you thinking that it had failed in the open, leaking gas and flooding the carb? If so, should I consider adding one?

Or are you thinking it failed, preventing gas to the carb? I've tried pouring gasdown the carb, but it didn't help.

 

[subzali]

No, sorry, I forgot that you have a Weber. If it fails on an OEM carb, the idle circuit won't work properly and you either have to keep it revved or hold the choke on for the truck to run. Advancing the timing also increases the rpm a bit (if you don't adjust the idle screw on the carb back down), so that's why I thought maybe it had something to do with that. I don't know though.

 

[Azrael]

Alright, I think I'm making progress. It doesn't look like I'm getting any spark across to board. Electrical look to be good up to that new coil. It looks like the point burnt out from arcing. I'm guessing I need to replace the point set and compressor. Can anyone confirm that that's what I'm looking at in this pic?

 

[Rzeppa]

Positive (moving arm) contact of the points looks likes toast, and that will stop you cold and prevent spark. When you replace the points, definitely make sure you have proper gap, around .018", or the thickness of a matchbook cover at the apex of the hex, max points opening. Then when you are done reset the timing.

Condensors rarely fail, but it is standard practice to replace them (when present) whenever the points are replaced.

After you replace the points, you should get spark, and should start and run. If not, come back here and we'll have more advice.

 

[Azrael]

Got a new battery and point set in today. Gapped the points as close as I could by eye, and it started right up and ran smooth. The dwell angle was about 39.5 which should be well within optimum range. After that, I was able to set the timing to 12º which is what I've heard suggested for the Weber. After that, I gave it a couple minutes to fully warm up before moving on to the carb. During that time, I gave it some gas to see if the hesitation was still there. At first it was, but then I realized the vacuum advance wasn't hooked up. Plugged that in, and the throttle was smooth and responsive. As soon as I let it off, it stalled, and blew smoke/vapor out of the carb. Now, I can't get it to start up again.

 

[Rzeppa]

That it started and ran eliminates a number of things. If I were you, I would pop the cap off and double check the points to make sure they are still opening - just in case the screws weren't tightened down after initial install. Don't ask me what made me think of this

Not that I ever did that

 

[Azrael]

I checked that first thing, and it was the case, but after readjusting it still wouldn't start. Also, the points bar seemed to already show signs of burning. Is that normal, or is something in there causing that to fail? I wasn't able to find a suitable condenser replacement, either. The ones I found didn't have a long enough mounting bracket to fit under the dist cap clamp.


Any ideas on what the smoke or vapor that shot out the carb would be from?

 

[Rzeppa]

I checked that first thing, and it was the case, but after readjusting it still wouldn't start. Also, the points bar seemed to already show signs of burning. Is that normal, or is something in there causing that to fail? I wasn't able to find a suitable condenser replacement, either. The ones I found didn't have a long enough mounting bracket to fit under the dist cap clamp.


Any ideas on what the smoke or vapor that shot out the carb would be from?

Good, one thing eliminated. Do you have voltage to the points? The burning may indicate (well it does indicate) that too much power was being dissipated. That may signal a shorted primary in the coil, or other short downstream from the points. Almost any cheap-a$$ed coil will work on older rigs that have points.

The condenser is a capacitor that is in parallel with the points. It reduces pitting and prolongs the life of the points, but the engine should run fine with no condenser at all. And with no condenser, the points should still last at least 10k miles. You could try disconnecting the condenser; it won't hurt anything, and would eliminate it as a cause of problems.

You should also re-check whether you have spark or not, and verify timing. F series engines are VERY tolerant of bad timing and will run if it is way off, but not optimally.

Smoke and vapor out of the carb suggest a REALLY bad timing problem - way too advanced or retarded - or points gap really screwed up. BTDT.

I assume this was probably accompanied by a backfire when it quit?

 

[Azrael]

Here's where I stand as of now:

After playing with it all day, I got it to run again, but not well enough to drive. The points do keep slipping a little bit, which stems from the fact that the ones I bought didn't fit exactly, and I had to dremel out one of the holes to make it fit. I think this keeps throwing my timing out of whack. Also, I reseated the dist. since it seemed like it was a gear off. This may have to be repositioned once I get the points gapped properly again. It did have the added benefit of improving the ground path to the block, though. After I did this, my spark checker was lighting up much brighter than before compared to a faint glow in the light. Also, before I did this, I switched back to the old jets to make sure I had enough gas to light.

So, as of now, I think I'm stuck trying to locate the correct points. From someone's suggestion in this thread, I believe it's the non-USA vacuum advance Dist. Anyone know where to get those? In town would be better. I went over to Stevenson, and they couldn't find it around anywhere. I'm going to head back over to the Checkers that I found the Niehoff points and see if they have other brands, in case I just got the wrong one.

 

[Rzeppa]

Here's where I stand as of now:

After playing with it all day, I got it to run again, but not well enough to drive. The points do keep slipping a little bit, which stems from the fact that the ones I bought didn't fit exactly, and I had to dremel out one of the holes to make it fit. I think this keeps throwing my timing out of whack. Also, I reseated the dist. since it seemed like it was a gear off. This may have to be repositioned once I get the points gapped properly again. It did have the added benefit of improving the ground path to the block, though. After I did this, my spark checker was lighting up much brighter than before compared to a faint glow in the light. Also, before I did this, I switched back to the old jets to make sure I had enough gas to light.

So, as of now, I think I'm stuck trying to locate the correct points. From someone's suggestion in this thread, I believe it's the non-USA vacuum advance Dist. Anyone know where to get those? In town would be better. I went over to Stevenson, and they couldn't find it around anywhere. I'm going to head back over to the Checkers that I found the Niehoff points and see if they have other brands, in case I just got the wrong one.

Excellent info!

For distributor positioning, refer to this post:

http://risingsun4x4club.org/forum2/showpost.php?p=14343&postcount=82

This is the "non-USA" distributor. I have a couple sets of new, OEM spare points, you are welcome to a free set if you don't mind driving to Kittredge.

Please elaborate on "dremel out the holes"? If you buggered up the threads you might have a screwed up backing plate for installing the correct points. I have a couple of spare distributors

lying around in case you might need parts.

 

[Azrael]

Well, mine looks like yours, but with a couple differences. The vacuum diaphragm is a bit different, and the condenser is on the outside. There's a screw for the condenser inside, but none of them seem to fit.

Here's the top view for comparison. You can see where I had to dremel the points set itself, because the mounting holes were a bit wider apart compared to the backing plate.

I didn't really expect that to last, but hoped it'd work temporarily. The points in your picture do look like the same set, though. If you don't mind giving up a set, I'd love to take one. It'd be very appreciated. By any chance are you coming to the meeting this week? If not, I'm sure I could swing by sometime. I'll be going on vacation next weekend, and driving all around the state, so I'm sure I could manage then.

Also, do you know the part number for reference?

 

[Rzeppa]

Well, mine looks like yours, but with a couple differences. The vacuum diaphragm is a bit different, and the condenser is on the outside. There's a screw for the condenser inside, but none of them seem to fit.

Here's the top view for comparison. You can see where I had to dremel the points set itself, because the mounting holes were a bit wider apart compared to the backing plate.

I didn't really expect that to last, but hoped it'd work temporarily. The points in your picture do look like the same set, though. If you don't mind giving up a set, I'd love to take one. It'd be very appreciated. By any chance are you coming to the meeting this week? If not, I'm sure I could swing by sometime. I'll be going on vacation next weekend, and driving all around the state, so I'm sure I could manage then.

Also, do you know the part number for reference?

Oh good, you didn't bugger up the backing plate, just the points themselves. Easily remedied with the proper points. Next time I'm in the garage I'll check on the P/N of the points and distributor.

I do plan to be at the meeting. Last month's was the first one I had missed since 2005.

 

[Azrael]

I do plan to be at the meeting.

Awesome. That sounds like the best plan. That'll give me two good reasons not to miss it now. It'd be nice to drive out in the 40, but I guess it can wait.

 

[Azrael]

She breathes live again. Got some good points ob there and got it up and running. Hooked the vacuum line up, and no hesitation at throttle at all. I had to move the distributor one tooth clockwise because as it was, the vacuum advance was hitting the oil filter before I could get the timing right. There was no way I could hook the tube on to it if I could get it running there. Will that cause any problems down the line?


Now I just got to get those new jets on it, and hopefully I'll be able to pass emissions tomorrow.

 

[MDH33]

Right on. Sounds like your patience and persistence with troubleshooting this are paying off.

 

[Azrael]

It was just in time, too. My car threw a CEL and started misfiring yesterday.

 

[subzali]

Do you have a hardtop for your truck? I've only ever seen it with a bikini...

Good work on the troubleshooting! It's usually something pretty simple!

 

[Azrael]

Do you have a hardtop for your truck? I've only ever seen it with a bikini...

No. That's the next endeavor, or at least a soft top. Any ideas where I can find one dirt cheap?